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	<1442903021-3893-3-git-send-email-mingo@kernel.org>
Date: Tue, 22 Sep 2015 10:48:56 -0700
Message-ID: <CA+55aFzN7MMoxzaq-mcNcNoVzUMr0aPHDTipU-OVdaz7_YZ12Q@mail.gmail.com>
Subject: Re: [PATCH 02/11] x86/mm/hotplug: Remove pgd_list use from the memory
 hotplug code
From: Linus Torvalds <torvalds@linux-foundation.org>
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Sender: owner-linux-mm@kvack.org
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To: Ingo Molnar <mingo@kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>, Andy Lutomirski <luto@amacapital.net>, Andrew Morton <akpm@linux-foundation.org>, Denys Vlasenko <dvlasenk@redhat.com>, Brian Gerst <brgerst@gmail.com>, Peter Zijlstra <peterz@infradead.org>, Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, Oleg Nesterov <oleg@redhat.com>, Waiman Long <waiman.long@hp.com>, Thomas Gleixner <tglx@linutronix.de>

On Mon, Sep 21, 2015 at 11:23 PM, Ingo Molnar <mingo@kernel.org> wrote:
> +
> +               for_each_process(g) {
> +                       struct task_struct *p;
> +                       struct mm_struct *mm;
>                         pgd_t *pgd;
>                         spinlock_t *pgt_lock;
>
> +                       p = find_lock_task_mm(g);
> +                       if (!p)
> +                               continue;
> +
> +                       mm = p->mm;

So quite frankly, this is *much* better than the earlier version that
walked over all threads.

However, this now becomes a pattern for the series, and that just makes me think

    "Why is this not a 'for_each_mm()' pattern helper?"

if it only showed up once, that would be one thing. But this
patch-series makes it a thing. Which is why I wonder..

                      Linus

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